Wednesday, March 13, 2013

Climate change: more data

Update, March 16: For more on the loss of the monarch habitat, see this Op-Ed in the New York Times.

Update, March 14: The New York Times is reporting that the monarch butterfly migration is the smallest in many years. If you have a subscription, read the article: first, I think it's fair to conclude that it illustrates that there are many unintended consequences from our decisions - weed-resistant plants mean fewer weeds, which means less food for the butterflies. And second, it illustrates the use of proxy measures - researchers cannot count the number of butterflies, so they count the amount of space the butterflies cover. The sharp declines are scary.

That is a graph showing temperature ranges over the last 11,000 years - the Holocene period, published last week in Science magazine (the full abstract is here; the full article is behind a paywall). What the data show is that the earth is warmer today than it's been for most of that period. What's different about this paper? Several things: it goes back much further than previous research and it examines global, not just regional, temperatures. As Tim McDonnell of The Climate Deskputs it:

To be clear, the study finds that temperatures in about a fifth of
this historical period were higher than they are today. But the key,
said lead author Shaun Marcott of Oregon State University, is that
temperatures are shooting through the roof faster than we've ever seen.

"What we found is that temperatures increased in the last hundred
years as much as they had cooled in the last six or seven thousand," he
said. "In other words, the rate of change is much greater than anything
we've seen in the whole Holocene," referring to the current geologic
time period, which began around 11,500 years ago.

How did we get here and where are we going? Here's a link to a good infographic that tells you what you need to know about the continuing release of carbon dioxide will play out in different scenarios. It's not a pretty picture.